Introduction
Celiac disease (CeD) affects up to 1.4% of the population but remains largely underdiagnosed (1), particularly in Southern Europe (2,3), with substantial diagnostic delay and healthcare burden (4,5). Symptom-based case finding performs poorly in adults due to the high prevalence of non-classical presentations (6-9). Simple, scalable screening strategies for primary care are urgently needed. The ITAMA_CAP study evaluated a real-world screening approach integrating a point-of-care test (PoCT) and a symptom-based case finding questionnaire in an unselected adult population.
Aims and Methods
We aimed to uncover undiagnosed CeD cases in the general adult population and to compare the diagnostic performance of PoCT versus a case finding questionnaire. In this prospective multicenter study, 160 Sicilian general practitioners consecutively screened adults (≥18 years) using capillary PoCT for qualitative detection of anti-tTG2 antibodies and a standardized case finding questionnaire. At-risk individuals (PoCT positive or ≥5 positive responses) underwent confirmatory serology (anti-tTG2 antibodies) and biopsy when indicated. Diagnostic accuracy metrics were estimated accounting for verification bias and compared using the Youden Index.
Results
A total of 6573 subjects were screened; 27.8% were referred for further testing. Thirty new CeD cases were identified (prevalence 0.45%), likely underestimated due to high dropout rates. PoCT positivity strongly predicted CeD (39.7% vs 0.96% in questionnaire-positive/PoCT-negative subjects; p<0.0001). Standalone PoCT showed excellent specificity (99.0%) and very high NPV (99.8%), with moderate sensitivity (81.1%). The questionnaire showed limited diagnostic value. Although the combined approach increased sensitivity (95.4%), this reduced specificity (~72%), lowering overall performance. PoCT was the strongest independent predictor of CeD (OR 100.39, p<0.001).
Conclusion
In primary care, PoCT outperforms symptom-based case finding for CeD screening in adults. Adding a questionnaire provides minimal benefit and reduces specificity. A PoCT-first strategy may improve detection, reduce unnecessary investigations, and address the hidden burden of CeD.